Pressure calibration method and touch sensitive process apparatus and touch system implementing the method

ABSTRACT

A pressure calibration method, applicable to a touch panel which sequentially comprises a first electrode layer, an elastic dielectric layer and a second electrode layer, the first electrode layer includes multiple first electrodes in parallel to a first axis, the second electrode layer includes multiple second electrodes in parallel to a second axis, the pressure calibration method comprising: retrieving a depression event according to mutual capacitance sensing between the first electrodes and the second electrodes; finding a corresponding calibration area according to coordinate of the depression event; when a calibration area where the touching event locates exists, taking the found calibration area as the corresponding calibration area; otherwise, taking a nearby calibration area which is closest to the touching event as the corresponding calibration area; and calculating a calibrated pressure value according to a pressure sensing value of the depression event and a pressure calibration function of the corresponding calibration area.

CROSS REFERENCE TO RELATED PATENT APPLICATION

This patent application is a divisional patent application of U.S.patent application Ser. No. 17/530,875, filed on Nov. 19, 2021, which isbased on a Taiwan, R.O.C. patent application No. 109146432 filed on Dec.25, 2020.

FIELD OF THE INVENTION

The present invention relates to touch sensitive control, and moreparticularly, to calibration of measured touch pressure.

BACKGROUND OF THE INVENTION

Touch panels or screens are common input devices of modern electronicdevices. In addition to specify a position by a stylus or a finger, usermay further control a force pressing to the touch panel. The control ofpressure improves user's experience.

However, touch panels may be made with defects or tolerances. Forexamples, widths of touch electrodes may be inconsistent or surface ofthe touch panel is slightly bended. When measuring pressure at differentlocations of the touch panel, different values would be gathered. Thus,it is desired to have a mechanism for calibrating pressure valuesmeasured by the touch panel such that error occurred in measurement canbe reduced.

SUMMARY OF THE INVENTION

The present application provides a pressure calibration method and atouch sensitive processing apparatus and a touch system for implementingthe pressure calibration method. Besides, the present application alsoprovides a pressure calibration function calculation method and a touchsensitive processing apparatus and a touch system for implementing thepressure calibration function calculation method. By dividing touchsurface of a touch panel into multiple smaller calibration areas andmeasuring at one or more vertexes of the calibration areas ascalibration points, a pressure calibration function corresponding to itscalibration area can be calculated so as the measured pressure errorcaused by local defects of the calibration area can be corrected.

According to an embodiment of the present application, a pressurecalibration method is provided. The pressure calibration method isapplicable to a touch panel which sequentially comprises a layer offirst electrodes, an elastic dielectric layer, and a layer of secondelectrodes. The layer of first electrodes includes multiple firstelectrodes in parallel to a first axis. The layer of second electrodesincludes multiple second electrodes in parallel to a second axis. Thepressure calibration method comprising: gathering a touching event byutilizing mutual capacitance sensing between the first electrodes andthe second electrodes; looking for a corresponding calibration areaaccording to coordinates of the touching event; and calculating acalibrated pressure value according to a measured pressure valuecorresponding to the touching event and a pressure calibration functioncorresponding to the calibration area.

According to an embodiment of the present application, a pressurecalibration method is provided. The pressure calibration method isapplicable to a touch panel which sequentially comprises a layer offirst electrodes, an elastic dielectric layer, a layer of secondelectrodes. The layer of first electrodes includes multiple firstelectrodes in parallel to a first axis. The layer of second electrodesincludes multiple second electrodes in parallel to a second axis. Thetouch panel further includes multiple third layers in parallel to thefirst axis. The pressure calibration method comprising: gathering anapproaching event by utilizing the second electrodes and the thirdelectrodes; gathering a touching event corresponding to the approachingevent by utilizing mutual capacitance sensing between the firstelectrodes and the second electrodes; looking for a calibration areaaccording to the approaching event; and calculating a calibratedpressure value according to a measured pressure value corresponding tothe approaching event and a pressure calibration function correspondingto the calibration area.

According to an embodiment of the present application, a touch sensitiveprocessing apparatus for pressure calibration is provided. The touchsensitive processing apparatus is coupled to a touch panel whichsequentially comprises a layer of first electrodes, an elasticdielectric layer, and a layer of second electrodes. The layer of firstelectrodes includes multiple first electrodes in parallel to a firstaxis. The layer of second electrodes includes multiple second electrodesin parallel to a second axis. The touch sensitive processing apparatuscomprising: an interconnection network, configured to connect to one ormore the first electrodes and one or more the second electrodes,respectively; a driving circuit, configured to connect to theinterconnection network for transmitting driving signals; a sensingcircuit, configured to connect to the interconnection network forsensing induced driving signals; and a processor, coupled to theinterconnection network, the driving circuit and the sensing circuit,configured to execute instructions stored in a non-volatile memory torealize the following steps: gathering a touching event by utilizingmutual capacitance sensing between the first electrodes and the secondelectrodes; looking for a corresponding calibration area according tocoordinates of the touching event; and calculating a calibrated pressurevalue according to a measured pressure value corresponding to thetouching event and a pressure calibration function corresponding to thecalibration area.

According to an embodiment of the present application, a touch sensitiveprocessing apparatus for pressure calibration is provided. The touchsensitive processing apparatus is coupled to a touch panel whichsequentially comprises a layer of first electrodes, an elasticdielectric layer, and a layer of second electrodes. The layer of firstelectrodes includes multiple first electrodes in parallel to a firstaxis. The layer of second electrodes includes multiple second electrodesin parallel to a second axis. The touch panel further includes multiplethird layers in parallel to the first axis. The touch sensitiveprocessing apparatus comprising: an interconnection network, configuredto connect to one or more the first electrodes, one or more the secondelectrodes and one or more the third electrodes, respectively; a drivingcircuit, configured to connect to the interconnection network fortransmitting driving signals; a sensing circuit, configured to connectto the interconnection network for sensing induced driving signals; anda processor, coupled to the interconnection network, the driving circuitand the sensing circuit, configured to execute instructions stored in anon-volatile memory to realize the following steps: gathering anapproaching event by utilizing the second electrodes and the thirdelectrodes; gathering a touching event corresponding to the approachingevent by utilizing mutual capacitance sensing between the firstelectrodes and the second electrodes; looking for a calibration areaaccording to the approaching event; and calculating a calibratedpressure value according to a measured pressure value corresponding tothe approaching event and a pressure calibration function correspondingto the calibration area.

According to an embodiment of the present application, a touch systemfor pressure calibration is provided. The touch system comprising theaforementioned touch sensitive processing apparatus; and the touch panelcoupled to the touch sensitive processing apparatus.

According to an embodiment of the present application, a pressurecalibration function calculation method is provided. The pressurecalibration function calculation method is applied to a touch panelwhich sequentially comprises a layer of first electrodes, an elasticdielectric layer, and a layer of second electrodes. The layer of firstelectrodes includes multiple first electrodes in parallel to a firstaxis. The layer of second electrodes includes multiple second electrodesin parallel to a second axis. The pressure calibration functioncalculation method comprising: by utilizing mutual capacitance sensingbetween the first electrodes and the second electrodes, measuringpressure values corresponding to calibration points when being pressedby a standard test pressure value, wherein the touch panel comprisesmultiple calibration areas and each calibration area corresponds to oneor more of the calibration points; and calculating a pressurecalibration function corresponding to each of the calibration areasaccording to coordinates of the calibration points, the standard testpressure value and the measured pressure values of the calibrationpoints.

According to an embodiment of the present application, a touch sensitiveprocessing apparatus for pressure calibration function calculation isprovided. The sensitive processing apparatus is coupled to a touch panelwhich sequentially comprises a layer of first electrodes, an elasticdielectric layer, and a layer of second electrodes. The layer of firstelectrodes includes multiple first electrodes in parallel to a firstaxis. The layer of second electrodes includes multiple second electrodesin parallel to a second axis. The touch sensitive processing apparatuscomprising: an interconnection network, configured to connect one ormore the first electrodes and one or more the second electrodes; adriving circuit, configured to transmit driving signals via theinterconnection network, a sensing circuit, configured to sense induceddriving signals via the interconnection network; and a processor,coupled to the interconnection network, the driving circuit and thesensing circuit, configured to execute instructions stored innon-volatile memory to realize the following steps: by utilizing mutualcapacitance sensing between the first electrodes and the secondelectrodes, measuring pressure values corresponding to calibrationpoints when being pressed by a standard test pressure value, wherein thetouch panel comprises multiple calibration areas and each calibrationarea corresponds to one or more of the calibration points; andcalculating a pressure calibration function corresponding to each of thecalibration areas according to coordinates of the calibration points,the standard test pressure value and the measured pressure values of thecalibration points.

According to an embodiment of the present application, a touch systemfor pressure calibration function calculation is provided. The touchsystem comprising the aforementioned touch sensitive processingapparatus; and the touch panel coupled to the touch sensitive processingapparatus.

BRIEF DESCRIPTION OF THE DRAWINGS

The advantages and spirit related to the present invention can befurther understood via the following detailed description and drawings.

FIG. 1 shows a block diagram of a touch system in accordance with anembodiment of the present invention.

FIGS. 2A-2D illustrates section views of touch screens in accordancewith embodiments of the present invention.

FIG. 3 depicts a top view of a touch screen in accordance with anembodiment of the present invention.

FIG. 4 illustrates calibration points and calibration areas inaccordance with an embodiment of the present application.

FIG. 5 illustrates calibration points and calibration areas inaccordance with an embodiment of the present application.

FIG. 6 illustrates special calibration points and a special calibrationarea in accordance with an embodiment of the present application.

FIG. 7 illustrates calibration areas according to an embodiment of thepresent application.

FIG. 8 illustrates calibration areas according to an embodiment of thepresent application.

FIG. 9 depicts a pressure calibration function calculation method inaccordance with an embodiment of the present application.

FIG. 10 depicts a pressure calibration method in accordance with anembodiment of the present application.

FIG. 11 depicts a pressure calibration method in accordance with anembodiment of the present application.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Some embodiments of the present application are described in detailsbelow. However, in addition to the description given below, the presentinvention can be applicable to other embodiments, and the scope of thepresent invention is not limited by such rather by the scope of theclaims. Moreover, for better understanding and clarity of thedescription, some components in the drawings may not necessary be drawnto scale, in which some may be exaggerated related to others, andirrelevant. If no relation of two steps is described, their executionorder is not bound by the sequence as shown in the flowchart diagram.

Please refer to FIG. 1 , which shows a block diagram of a touch system100 in accordance with an embodiment of the present invention. The touchsystem 100 may be a computer system such as a desktop computer, a laptopcomputer, a tablet computer, an industrial control computer, asmartphone or any other kinds of computer having touch sensitivefunction.

The touch system 100 may comprise a touch sensitive processing apparatus110, a touch panel or screen 120 coupled to the touch sensitiveprocessing apparatus 110, and a host coupled to the touch sensitiveprocessing apparatus 110. The touch system 100 may further comprises oneor more styli 130 and/or touch board eraser 135. Hereinafter the touchpanel or screen 120 is referred as the touch screen 120. However, in theembodiments lacking of display function, persons having ordinary skillin the art can understand the touch screen denoted in the presentapplication may be referred to a touch panel.

The touch screen 120 may comprise multiple first electrodes 121 inparallel to a first axis, multiple second electrodes 122 in parallel toa second axis and one or more third electrodes 123. The first electrodes121 may intersect with the second electrodes 122 in order to formmultiple sensing points or sensing areas. Equivalently, the secondelectrodes 122 may intersect with the first electrodes 121 in order toform multiple sensing points or sensing areas. In some embodiments ofthe present application, the first electrodes 121 may be referred asfirst touch electrodes 121, the second electrodes 122 may be referred assecond touch electrodes 122, and the third electrodes 123 may bereferred as third touch electrodes 123. The first electrodes 121, thesecond electrodes 122 and the third electrodes 123 may be collectivelyreferred as touch electrodes. In some embodiments with touch screens120, the first electrodes 121, the second electrodes 122 and the thirdelectrodes 123 are made by transparent material. The first electrodes121 and the second electrodes 122 may be disposed in one electrodelayer. Conductive plates of each one of the first electrodes 121 or thesecond electrodes 122 may be connected by bridging. The first electrodes121 and the second electrodes 122 may be disposed at differentoverlapping electrode layers. Unless described specifically, the presentapplication may be applied to the embodiments having one or moreelectrode layers. The first axis and the second axis are perpendicularin most cases. However, the present application does not limit that thefirst axis and the second axis are perpendicular. In one embodiment, thefirst axis may be a horizontal axis or a pixel refreshing axis of thetouch screen 120.

Please refer to FIG. 2A, which illustrates a section view of a touchscreen 120 in accordance with an embodiment of the present invention.The touch screen 120 comprises a structure including the aforementionedelectrode layers. The structure sequentially includes a layer of thirdelectrodes 123, an elastic dielectric layer 124, a layer of secondelectrodes 122, a dielectric layer 125 and a layer of first electrodes121. Persons having ordinary skill in the art can understand that thetouch screen 120 may include other display structures or layers whichare omitted in order to clearly show the inventive features.

The layer of third electrodes 123 is closest to an external object or anexternal conductive object 139 like a finger. The elastic dielectriclayer 124 is sandwiched in between the layer of third electrodes 123 andthe layer of second electrodes 122 in order to isolate the secondelectrodes 122 from the third electrodes 123. When the external object139 downwardly contacts the touch screen 120, the layer of thirdelectrodes 123 and the elastic dielectric layer 124 deforms because ofbeing pressed. Accordingly, distances between the layer of thirdelectrodes 123 and the layer of second electrodes 123 are shortened.Capacitances between the second electrodes 122 and the third electrodes123 are changed according to the varied distances.

Please refer to FIG. 2B, which illustrates a section view of a touchscreen 120 in accordance with an embodiment of the present invention.Comparing with the embodiment as shown in FIG. 2A, the elasticdielectric layer 124 as shown in FIG. 2B is sandwiched in between thelayer of first electrodes 121 and the layer of second electrodes 122.The dielectric layer 125 is sandwiched in between the layer of thirdelectrodes 123 and the layer of second electrodes 122 in order toisolate the second electrodes 122 from the third electrodes 123. Whenthe external conductive object 139 downwardly contacts the touch screen120, the elastic dielectric layer 124 deforms because of being pressed.Accordingly, distances between the layer of first electrodes 121 and thelayer of second electrodes 122 are shortened. Capacitances between thefirst electrodes 121 and the second electrodes 122 are changed accordingto the varied distances.

Please refer to FIG. 2C, which illustrates a section view of a touchscreen 120 in accordance with an embodiment of the present invention.The elastic dielectric layer 124 as shown in FIG. 2B is sandwiched inbetween the layer of first electrodes 121 and the layer of secondelectrodes 122. When the external object 139 downwardly contacts thetouch screen 120, the elastic dielectric layer 124 deforms because ofbeing pressed. Accordingly, distances between the layer of firstelectrodes 121 and the layer of second electrodes 122 are shortened.Capacitances between the first electrodes 121 and the second electrodes122 are changed according to the varied distances.

Please refer to FIG. 2D, which illustrates a section view of a touchscreen 120 in accordance with an embodiment of the present invention.The multiple third electrodes 123 and the multiple second electrodes 122are disposed in one layer. Each of the second electrodes 122 intersectswith the third electrodes 123 at their bridging parts. The thirdelectrodes 123 may be in parallel to the first axis like the firstelectrodes 121.

In the embodiment as shown in FIG. 2A, since the layer of thirdelectrodes 123 is adjacent to the layer of second electrodes 122, thethird electrodes 123 are in parallel to the first axis like the firstelectrodes 121. In the embodiment as shown in FIG. 2B, since the layerof third electrodes 123 is adjacent to the layer of first electrodes121, the third electrodes 123 are in parallel to the second axis likethe second electrodes 122. However, the present application does notlimit that the third electrodes 123 shall be in parallel to differentaxes with electrodes in the adjacent layer.

The touch sensitive processing apparatus 110 as shown in FIG. 1 maycomprise following hardware circuit: an interconnection network 111, adriving circuit 112, a sensing circuit 113, a processor 114, and aninterface 115. The touch sensitive processing apparatus 110 may beimplemented inside a single integrated circuit which may include one ormore chips. It may use multiple integrated circuits and aninterconnected circuit board carried the multiple integrated circuits torealize the touch sensitive processing apparatus 110. The touchsensitive processing apparatus 100 may be implemented in singleintegrated circuits with the host 140. The present application does notlimit how to implement the touch sensitive processing apparatus 110.

The interconnection network 111 is configured to connect each of themultiple first electrodes 121, the multiple second electrodes 122 and/orthe multiple third electrodes 123 of the touch screen 120. Theinterconnection network 111 may follow control command of the processor114 for connecting the driving circuit 112 and any one or more touchelectrodes and for connecting the sensing circuit 113 and any one ormore touch electrodes. The interconnection network 111 may include acombination of one or more multiplexers (MUX) to realize theaforementioned functions.

Please refer to FIG. 3 which depicts a top view of a touch screen 120 inaccordance with an embodiment of the present invention. Theinterconnection network 111 may be used to connect the driving circuit112 and/or the sensing circuit 113 to one or more of the firstelectrodes 121 or the second electrodes 122, respectively. The presentapplication does not limit the way the interconnection network 111 usesingle routing or double routing to connect each of the first electrodes121 and the second electrodes 122. In one embodiment, when the number ofthe third electrodes 123 is identical to the number of the firstelectrodes 121 and each one of the first electrodes 121 is verticallyprojected to one of the third electrodes 123, the first electrodes 121as shown in FIG. 3 may be replaced by the third electrodes 123. That is,each of the second electrodes 122 intersects with all of the firstelectrodes 121 and all of the third electrodes 123 to form intersectionareas.

The driving circuit 112 as shown in FIG. 1 may comprise clock generator,frequency divider, frequency multiplier, phase lock loop, poweramplifier, DC-DC voltage converter, regulator and/or filter, which isconfigured to provide driving signal to any one or more touch electrodesvia the interconnection network 111 according to control commands of theprocessor 114. The driving signal may be modulated by kinds of analog ordigital modulations for carrying some messages. The modulations includebut not limit to frequency modulation (FM), phase modulation, amplitudemodulation, dual sideband modulation (DSB), single sideband module(SSB-AM), vestigial sideband modulation, amplitude shift keying (ASK),phase shift keying (PSK), quadrature amplitude modulation (QAM),frequency shift keying (FSK), continuous phase modulation (CPM), codedivision multiple (CDMA), time division multiple access (TDMA),orthogonal frequency division multiplexing (OFDM), pulse widthmodulation (PWM) and etc. The driving signal may include one or moresquare waves, sinuous waves or any modulated waves. The driving circuit112 may include one or more channel. Each channel may be connected toany one or more touch electrodes via the interconnection network 111.

The sensing circuit 113 may comprise clock generator, frequency divider,frequency multiplier, phase lock loop, power amplifier, DC-DC voltageconverter, regulator and/or filter, which is configured to sense on anyone or more touch electrodes via the interconnection network 111according to control commands of the processor 114. When the touchsignal is transmitted from one of the touch electrodes, another touchelectrode may induce the touch signal. And the sensing circuit 130 maydemodulate the induced touch signal by the another touch electrode inaccordance with the modulation method performed on the driving signal bythe driving circuit 112 in order to restore the messages carried by thedriving signal. The sensing circuit 113 may include one or morechannels. Each channel may be connected to any one or more touchelectrodes via the interconnection network 111. In the same time, eachchannel may simultaneously perform sensing and demodulation.

In one embodiment, the driving circuit 112 and the sensing circuit 113may include analog front-end (AFE) circuits. In another embodiment, inadditional to the AFE circuits, the driving circuit 112 and the sensingcircuit 313 may include digital back-end (DBE) circuits. If the drivingcircuit 112 and the sensing circuit 113 include only the AFE circuits,the DBE circuits may be implemented in the processor 114.

The processor 114 may include a digital signal processor for connectingthe AFE circuits or the DBE circuits of the driving circuit 112 and thesensing circuit 113, respectively. The processor 114 may include anembedded processor, non-volatile memories and volatile memories. Normalor real-time operating system (OS) and their application programs may bestored in the non-volatile memories. The OS and the application programsinclude multiple instructions and data. The processor (including theembedded processor and the digital signal processor) may execute theinstructions for controlling other modules including the interconnectionnetwork 111, the driving circuit 112, the sensing circuit 113 and theinterface 115 of the touch sensitive processing apparatus 110. Forexamples, the processor 114 may comprises processors widely adopted inthe industry such as 8051 series, Intel i960 series, ARM Cortex-M seriesand etc. The present application does not limit types and numbers ofprocessor cores included in the processor 114.

The instructions and data may be used to implement each of stepsmentioned in the present application and flows and methods constructedby the steps. Some instructions may be executed independently inside theprocessor 114, for examples, arithmetic and log operation instructions.Other instructions may be used to control other circuits of the touchsensitive processing apparatus 110. These instructions may includeinput/output interfaces of the processor 114 to control other circuits.Other circuits may provide information via the input/output interface ofthe processor 114 to the OS and/or application programs executed by theprocessor 114. Persons having ordinary skill in the art should havecommon knowledge of computer organization and architecture whichenabling them to understand that the flows and methods provided by thepresent application can be realized by the circuits and theinstructions.

The interface 115 may include kinds of serial or parallel bus, such asuniversal serial bus (USB), I²C, peripheral component interconnect(PCI), PCI-Express, IEEE 1394 and other industrial standard input/outputinterface. The touch sensitive processing apparatus 110 connects to thehost 140 via the interface 115.

The touch system 100 may comprise one or more styli 130 and/or touchboard erasers 135. The stylus 130 and touch board eraser 135 may betransmitters which emit electrical signals. The transmitters may includeactive transmitter which actively emits electrical signals or passivetransmitters which emit electrical signals in response to externalelectrical signals. The stylus 130 and touch board eraser 135 maycomprise one or more electrodes which is configured to receiveelectrical signals from the touch screen 120 synchronously orasynchronously, or to transmit electrical signals to the touch screen120 synchronously or asynchronously. The electrical signals may bemodulated according to one or more of the aforementioned modulationmethods.

The stylus 130 or touch board eraser 135 may be conductor which isconfigured to transmit driving signals or to be grounded via user's handor body. The stylus 130 or touch board eraser 135 may be physically orwirelessly connected to an I/O interface 141 of the host 140 or anyother interfacing circuits of the I/O interface 141.

The touch sensitive processing apparatus 110 may detect one or moreexternal objects 139 such as fingers, palms or passive styli 130 ortouch board erasers 135, or active styli 130 or touch board erasers 135emitting electrical signals via the touch screen 120. The touchsensitive processing apparatus 110 may utilize mutual-capacitancesensing or self-capacitance sensing to detect external conductiveobjects. The styli 130 or touch board erasers 135 and touch sensitiveprocessing apparatus 110 may use the aforementioned modulation anddemodulation methods to transmit message via the electrical signals. Thetouch sensitive processing apparatus 110 may detect one or morepositions where the styli 130 or touch board erasers 135 touch orapproach the touch screen 120, status or sensors (pressure sensor orbutton) onboard the stylus 130 or touch board eraser 135, orientationangle or inclination angle of the stylus 130 or touch board eraser 135with respect to the touch screen 120, and etc. according to theelectrical signals.

The host 140 is a main apparatus for controlling the touch system 100.It may comprises an input/output interface 141 for connecting theinterface 115, a central processing unit (CPU) 142, a graphics processor143, a memory 144 connects to the CPU 142, a network interface 145 and astorage 146 connect to the input/output interface 141.

The storage 146 comprises non-volatile memory. Common examples are harddisks, electronic erasable rewritable read only memory (EEPROM), orflash memory. The storage 146 may store normal operating system andapplication programs executable under the operating system. The networkinterface 145 may comprise wired or wireless hardware network interface.The network interface 145 may be compliant to common industrialstandards such as IEEE 802.11 Wireless Local Area Network, IEEE 802.3Local Area Network, 3G, 4G and/or 5G wireless telecommunicationstandards, Bluetooth wireless communication standards, and etc.

The CPU 142 may directly or indirectly connects to the input/outputinterface 141, the graphics processor 143, the memory 144, the networkinterface 145 and the storage 146. The CPU 142 may comprise one or moreprocessor or processor cores. Common processors may include Intel, AMD,VIA's x86 and x64 instruction set architecture (ISA) processors, Apple,Qualcomm, MediaTek's ARM ISA processors, or any other types of complexinstruction set computer (CISC) or reduced instruction set computer(RISC) processors. The OS and application programs include multipleinstructions and data corresponding to the instruction set. By executingthese instructions, the CPU 142 is able to control other circuits of thetouch system 100.

The optional graphics processor (GPU) 143 is usually configured tohandle computations with respect to graphics outputs. The graphicsprocessor 143 may connect to the touch screen 120 for controllingoutputs of the touch screen 120. In some applications, the host 140 mayhave the CPU 142 execute the computations with respect to graphicsoutputs, without dedicated handling of the graphics processor 143.

The host 140 may comprise components or apparatus not shown in FIG. 1 ,for example, audio input/output interface, keyboard input interface,mouse input interface, track-ball input interface and/or any otherhardware circuits. Persons having ordinary skill in the art should havecommon knowledge of computer organization and architecture. They canunderstand the touch system 100 disclosed by the present application isexemplary. Parts regarding to the inventive feature provided by thepresent application should be referred to the specification and theclaim.

Please refer to FIG. 4 , which illustrates calibration points andcalibration areas in accordance with an embodiment of the presentapplication. Multiple calibration points may be designated on the touchscreen 120. There are 9 calibration points 411˜433 in the embodiment asshown in FIG. 4 . However, person having ordinary skill in the art canunderstand that it is possible to designate 12, 16, 15 or any othernumber of calibration points on the touch screen 120.

In one embodiment, a calibration point may be located at an intersectionof one of the second electrodes 122 and one of the first electrodes 121or at an intersection of one of the second electrodes 122 and one of thethird electrodes 123. In one embodiment, each one of the intersectionsthat the second electrodes 122 intersect with other touch electrodes isa calibration point. In other words, the number of calibration pointsequals to the number of intersections. Person having ordinary skill inthe art can understand that a calibration point may be designated to apoint which is other than an intersection. However, since capacitancevalues at or near edges of the touch screen 120 are different from thoseat the internal areas of the touch screen 120, the calibration pointsmay not be designated at or around the edges of the touch screen 120.

Three kinds of calibration areas may be found in the embodiment as shownin FIG. 4 . First kind of calibration areas, e.g., multiple firstcalibration areas 461˜463, are disposed in the internal area of thetouch screen 120. Each of the first calibration areas is a rectangle.Its four vertexes are all calibration points. The first calibrationareas are not disposed at the edges of the touch screen 120. Second kindof calibration areas, e.g., multiple second calibration areas 451˜458,are disposed at the edges of the touch screen 120. Each one of thesecond calibration areas is a rectangle having two adjacent vertexes ascalibration points. The second calibration area share one edge with thetouch screen 120. Third kind of calibration areas, e.g., multiple thirdcalibration areas 441˜444, are disposed at the corners of the touchscreen 120. Only one of the vertexes of the third calibration areas is acalibration point. Two adjacent edges of the third calibration areashare two edges of the touch screen 120.

In one embodiment, shapes and area sizes of the first calibration areaare identical; shapes and area sizes of every second calibration areasare identical; and shapes and area sizes of every third calibrationareas are identical. However, person having ordinary skill in the artcan understand a shape and an area size of a given calibration area maybe different from any other calibration areas.

A purpose to designate a calibration area is to establish a pressurecalibration function corresponding to the calibration area. Thecalibration function may be generated according to measured values ofmultiple calibration points. For example, a pressure calibrationfunction corresponding to a first calibration area may be generatedaccording to measured values of four calibration points at its fourvertexes. A pressure calibration function corresponding to a secondcalibration area may be generated according to measured values of twocalibration points at its two vertexes or may be a copy of a pressurecalibration function corresponding to its adjacent first calibrationarea. For example, the pressure calibration function of the secondcalibration area 451 may be a copy of the pressure function of itsadjacent first calibration area 461. The pressure calibration functionof the second calibration area 456 may be a copy of the pressurefunction of its adjacent first calibration area 464. With regard to apressure calibration function of a third calibration area, it may be acopy of a pressure calibration function of its adjacent calibrationarea. For example, the pressure calibration function of the thirdcalibration area 441 may be a copy of the pressure calibration of thefirst calibration area 461 or a copy of the pressure calibrationfunction of the second calibration area 451 or 453.

An example of so-called pressure calibration function is referred to afunction with a measured pressure value as its input. The output of thepressure calibration function is a calibrated pressure value. In oneembodiment, a pressure calibration function f is expressed in Formula 1.

ƒ(P _(m))=P _(c) =r·P _(m) +e  (Formula 1)

where P_(m) is a measured pressure value, P_(c) is a calibrated pressurevalue, r is a coefficient of calibration, e is an error value.

Except for the aforementioned formula, person having ordinary skill inthe art may understand that the so-called pressure calibration functionmay be realized by a quadratic function. When the error value e is aconstant value, e.g., e may be zero, a pressure calibration functioncorresponding to a first calibration area may be generated as follow. Incase a pressure force Pc is applied to a particular calibration point bya tool, a pressure value Pm is measured. Given a constant as the errorvalue e, a coefficient r corresponding to the calibration point can becalculated according to Formula 1. Assuming that coordinates of the fourcalibration points are (x₀, y₀), (x₁, y₀), (x₁, y₁) and (x₀, y₁), fourcoefficients corresponding to the four calibration points can becalculated as r_(0,0), r_(1,0), r_(1,1) and r_(0,1), respectively. Next,a coefficient r corresponding to a point at (x, y) can be calculatedaccording to Formula 2. Thus, the pressure calibration functionapplicable to the first calibration area is generated accordingly.

$\begin{matrix}{r = {r_{0,0} + {\frac{r_{0,1} - r_{0,0}}{y_{1} - y_{0}}( {y - y_{0}} )} + {\frac{r_{1,0} - r_{0,0}}{x_{1} - x_{0}}( {x - x_{0}} )} + {\frac{( {r_{1,1} + r_{0,0}} ) - ( {r_{1,0} + r_{0,1}} )}{( {y_{1} - y_{0}} )( {x_{1} - x_{0}} )}( {x - x_{0}} )( {y - y_{0}} )}}} & ( {{Formula}2} )\end{matrix}$

With regard to the second calibration areas 451, 452, 457 and 458, they-axis coordinate of the two calibration points are identical. These twocalibration points are located at (x₀, y₀) and (x₁, y₀). Twocoefficients r_(0,0) and r_(1,0) can be calculated according to theaforementioned method. In one embodiment, Formula 3 can be deduced fromFormula 2 to calculate a coefficient r corresponding to a point at (x,y). Thus, the pressure calibration function applicable to the secondcalibration areas 451, 452, 457 and 458 is generated accordingly.

$\begin{matrix}{r = {r_{0,0} + {\frac{r_{1,0} - r_{0,0}}{x_{1} - x_{0}}( {x - x_{0}} )}}} & ( {{Formula}3} )\end{matrix}$

With regard to the second calibration areas 453, 454, 455 and 456, thex-axis coordinate of the two calibration points are identical. These twocalibration points are located at (x₀, y₀) and (x₀, y₁). Twocoefficients r_(0,0) and r_(0,1) can be calculated according to theaforementioned method. In one embodiment, Formula 4 can be deduced fromFormula 2 to calculate a coefficient r corresponding to a point at (x,y). Thus, the pressure calibration function applicable to the secondcalibration areas 453, 454, 455 and 456 is generated accordingly.

$\begin{matrix}{r = {r_{0,0} + {\frac{r_{1,0} - r_{0,0}}{y_{1} - y_{0}}( {y - y_{0}} )}}} & ( {{Formula}4} )\end{matrix}$

Only one calibration point is included in the third calibration areas441˜444. In one embodiment, the pressure calibration function applicableto the third calibration areas may reuse the coefficient r and the errore corresponding to the only one calibration point.

Please refer to FIG. 5 , which illustrates calibration points andcalibration areas in accordance with an embodiment of the presentapplication. In the embodiment as shown in FIG. 5 , the rectangularfirst calibration areas as shown in FIG. 4 are divided into twotriangular fourth calibration areas. For examples, the first calibrationarea 461 is divided into two fourth calibration areas 561 and 562. Thefirst calibration area 462 is divided into two fourth calibration areas563 and 564. The division methods applied to these two first calibrationareas 461 and 462 may be different. The former is dissected by adiagonal line between the upper left vertex and the lower right vertex.The latter is divided by a diagonal line between the upper right vertexand the lower left vertex. Person having ordinary skill in the art canunderstand that a triangular fourth calibration area is defined by anygiven three calibration points. Since the second and the thirdcalibration area have less than three calibration points, they may notbe divided further.

Given that the coordinates of three calibration points are (x₀, y₀),(x₁, y₀) and (x₁, y₁), three coefficient values r_(0,0), r_(1,0) andr_(1,1) can be calculated according to the aforementioned method. Next,a coefficient r corresponding to a point at (x, y) can be calculatedaccording to Formula 5. Thus, the pressure calibration functionapplicable to the fourth calibration areas is generated accordingly.

$\begin{matrix}{r = {r_{0,0} + {\frac{r_{1,0} - r_{0,0}}{x_{1} - x_{0}}( {x - x_{0}} )} + {\frac{r_{1,1} - r_{1,0}}{y_{1} - y_{0}}( {y - y_{0}} )}}} & ( {{Formula}5} )\end{matrix}$

Given that the coordinates of three calibration points are (x₀, y₀),(x₀, y₁) and (x₁, y₁), three coefficient values r_(0,0), r_(0,1) andr_(1,1) can be calculated according to the aforementioned method. Next,a coefficient r corresponding to a point at (x, y) can be calculatedaccording to Formula 6. Thus, the pressure calibration functionapplicable to the fourth calibration areas is generated accordingly.

$\begin{matrix}{r = {r_{0,0} + {\frac{r_{0,1} - r_{0,0}}{y_{1} - y_{0}}( {y - y_{0}} )} + {\frac{r_{1,1} - r_{0,1}}{x_{1} - x_{0}}( {x - x_{0}} )}}} & ( {{Formula}6} )\end{matrix}$

With regard to the embodiments as shown in FIGS. 4 and 5 , a differencebetween the measured pressure value and the calibrated pressure valuecorresponding to a calibration point may be allowed to fall into arange. However, in case that the difference corresponding to a specifiedcalibration point is out of the range, more special calibration pointsmay be designated to peripheral points around the specified abnormalcalibration point. A special calibration area is formed by the abnormalspecified calibration point and its corresponding special calibrationpoints. A particular pressure calibration function applied to thespecial calibration area can be calculated accordingly.

Please refer to FIG. 6 , which illustrates special calibration pointsand a special calibration area in accordance with an embodiment of thepresent application. In the embodiment as shown in FIG. 6 , the measuredpressure value corresponding to the calibration point 422 is abnormal.However, the difference shows it's corresponding to a still acceptabledefect. Hence, multiple special calibration points 611, 612, 621 and 622are designated around the abnormal calibration point 422. A specialcalibration area 610 is formed by the special calibration points 611,612, 621 and 622. And the abnormal calibration point 422 resides insidethe special calibration area 610. Besides, a triangular calibration area(not shown) is formed by the special calibration points 611, 612, 622.And the abnormal calibration point 422 resides inside the specialtriangular calibration area, too.

In one embodiment, the calibration measurement method can be applied tothe rectangular special calibration area. Next, Formula 2 may be appliedto generate the pressure calibration function corresponding to thespecial calibration area. In an alternative embodiment, the calibrationmeasurement method can be applied to the triangular special calibrationarea. Next, Formula 5 or Formula 6 may be applied to generate thepressure calibration function corresponding to the special calibrationarea. However, when applying Formula 2, two adjacent edges of therectangular calibration area have to be in parallel to long edge andshort edge of the touch screen 120, respectively. In order to utilizingFormula 5 or 6, two adjacent edges of the triangular calibration areahave to be in parallel to long edge and short edge of the touch screen120, respectively, too.

If one of measured pressure values corresponding to the three or fourspecial calibration points is out of the normal range, all of thesespecial calibration points may be abandoned. A larger specialcalibration area containing the original special calibration area may bedesignated until all of measured pressure values corresponding to allspecial calibration points of the larger special calibration area are inthe normal range. After that, the pressure calibration functioncorresponding to the larger special calibration area can be derived.

Please refer to FIG. 7 , which illustrates calibration areas accordingto an embodiment of the present application. In the embodiment as shownin FIG. 7 , each intersection of the first electrodes 121 and the secondelectrodes 122 is a calibration point. Being applied to the embodimentas shown in FIGS. 2B and 2C, the elastic dielectric layer 124 isdisposed in between the first electrodes 121 and the second electrodes122. However, when applying to the embodiment as shown in FIG. 2A, eachintersection of the second electrodes 122 and the third electrodes 123is a calibration point.

Since the present application utilizes changes of mutual capacitancecaused by the thickness of the elastic dielectric layer 124 to detectpressure values. Measured pressure values corresponding to all theintersections can form a two-dimensional pressure value image fordetecting one or more external objects. In this embodiment as shown inFIG. 7 , many first calibration areas 760 which have identical shape andarea size are designated. Based on the two-dimensional pressure valueimage and Formula 2, pressure calibration functions corresponding tothese first calibration areas 760 can be found.

Please refer to FIG. 8 , which illustrates calibration areas accordingto an embodiment of the present application. Like the embodiment asshown in FIG. 7 , each intersection of the first electrodes 121 and thesecond electrodes 122 is a calibration point. Being applied to theembodiment as shown in FIGS. 2B and 2C, the elastic dielectric layer 124is disposed in between the first electrodes 121 and the secondelectrodes 122. However, when applying to the embodiment as shown inFIG. 2A, each intersection of the second electrodes 122 and the thirdelectrodes 123 is a calibration point.

In this embodiment, many fourth calibration areas 861 and 862 aredesignated. Based on the two-dimensional pressure value image, pressurecalibration functions corresponding to these fourth calibration areas861 and 862 with identical area size can be found according to Formula 5and Formula 6, respectively.

Please refer to FIG. 9 , which depicts a pressure calibration functioncalculation method in accordance with an embodiment of the presentapplication. The pressure calibration function calculation method 900may be realized by the touch sensitive processing apparatus 110 as shownin FIG. 1 . Especially, the method may be implemented as a group ofinstructions and data stored in non-volatile memory and the instructionsbeing executable by the processor 114. If no causal relationship ismentioned, the present application does not limit the execution order ofany given two steps. The pressure calibration function calculationmethod 900 begins at step 910.

Step 910: dividing the touch sensitive area into multiple calibrationareas. Each of the calibration areas includes at least one calibrationpoint. For examples, the aforementioned first, second, third and fourthcalibration areas. Each of the calibration areas may include twoadjacent edges which are in parallel to two adjacent edges of the touchscreen, respectively.

Step 920: gathering measured pressure values corresponding to thecalibration points of the calibration areas by utilizing mutualcapacitance sensing mechanism. The mutual capacitance sensing is todetect changes of mutual capacitance values caused by changes ofdistances between two touch electrodes. At this step, a verifiedstandard test pressure is applied to the calibration points and themeasured pressure values corresponding to the calibration points aresensed, respectively. In case a calibration point is at an intersectionof the two touch electrodes, a variation of sensing values correspondingto the calibration point may be viewed as the measured pressure value.Alternatively, in case the calibration point is not designated at anintersection of the two touch electrodes, person having ordinary skillin the art can understand that the measured pressure value correspondingto the calibration point can be calculated according to thetwo-dimensional pressure value image gathered by utilizing mutualcapacitance sensing mechanism. Next, the flow may proceed to optionalstep 930 or to step 960.

Optional step 930: determining whether any one of the measured pressurevalues is out of a range. In case there is, the flow proceeds to step940. Otherwise, the flow proceeds to step 960. The range may be definedby a low value and a high value. A normal measured pressure valueresides in between the low and the high values.

Step 940: designating a special calibration area corresponding to eachof abnormal calibration points. The special calibration area may includethe corresponding abnormal calibration point. If the abnormalcalibration point resides at an edge of the touch screen, the abnormalcalibration point may be one vertex of the special calibration area.

Step 950: similar to step 920, gathering measured pressure valuescorresponding to the special calibration points of the specialcalibration area(s) by utilizing mutual capacitance sensing mechanism.

Step 960: generating pressure calibration functions corresponding to thecalibration areas according to the measured pressure values of thecalibration points. The pressure calibration function calculation method900 may generate the pressure calibration function corresponding to eachof the calibration areas. The second calibration areas reside around theedges may reuse the pressure calibration function corresponding to theadjacent first or fourth calibration area or the pressure calibrationfunction generated according to Formula 3 or Formula 4. The thirdcalibration areas at the corners may reuse the pressure calibrationfunction corresponding to the adjacent first or fourth calibration areaor reuse the pressure calibration function corresponding to its only onecalibration point. In an embodiment, it does not bother to generatepressure calibration functions corresponding to the second calibrationareas residing around the edges and generate pressure calibrationfunctions corresponding to the third calibration areas residing at thecorners. In other words, it does not designate the second calibrationareas and/or the third calibration areas in order to preserve memoryspace from saving their corresponding pressure calibration functions.

Please refer to FIG. 10 , which depicts a pressure calibration method inaccordance with an embodiment of the present application. The pressurecalibration method 1000 may be applied to the touch screens 120 as shownin FIGS. 2A through 2C and be realized by the touch sensitive processingapparatus 110 as shown in FIG. 1 . Especially, the method may beimplemented as a group of instructions and data stored in non-volatilememory and the instructions being executable by the processor 114. If nocausal relationship is mentioned, the present application does not limitthe execution order of any given two steps. The pressure calibrationmethod 1000 begins at step 1010.

Step 1010: gathering a touching event by utilizing mutual capacitancesensing. When an external object touches and presses the touch screen120, distances between the touch electrodes are shortened and mutualcapacitance values would be changed accordingly. Person having ordinaryskill in the art can understand that a two dimensional pressure valueimage can be gathered by utilizing mutual capacitance sensing. Hence,coordinates and measured pressure values corresponding to the touchingevent can be calculated according to the two-dimensional pressure valueimage.

Step 1020: looking for a calibration area according to the coordinatesof the touching event. If all of the areas around the corners and theedges of the touch screen 120 are corresponding to their calibrationareas, the flow may directly proceeds to step 1050. However, if theareas around the corners and the edges of the touch screen 120 are notdesignated to a calibration area, the flow may proceed to step 1030:

Step 1030: determining whether the touching event is not correspondingto a calibration area. In case the touching event is happened around thecorners or the edges of the touch screen 120, the flow may proceed tostep 1040. Otherwise, the flow proceeds to step 1050

Step 1040: looking for the closest calibration area according to thecoordinates of the touching event. As discussed above, the closest firstcalibration area or the fourth calibration area may be designated as thecorresponding calibration area.

Step 1050: calculating a calibrated pressure value according to themeasured pressure value of the touching event and the pressurecalibration function of the corresponding calibration area. Thus, thetouch sensitive processing apparatus 110 may update the pressure valuecorresponding to the touching event and report the touching event to thehost 140.

Please refer to FIG. 11 , which depicts a pressure calibration method inaccordance with an embodiment of the present application. The pressurecalibration method 1100 may be applied to the touch screens 120 as shownin FIGS. 2A and 2B and be realized by the touch sensitive processingapparatus 110 as shown in FIG. 1 . Especially, the method may beimplemented as a group of instructions and data stored in non-volatilememory and the instructions being executable by the processor 114. If nocausal relationship is mentioned, the present application does not limitthe execution order of any given two steps. The pressure calibrationmethod 1100 begins at step 1110.

The touch screens 120 as shown in FIGS. 2A, 2B and 2D can be used togather approaching events and touching events. The approaching event maybe detected by changes of mutual capacitance values in between two touchelectrodes caused by a nearby external conductive object. Hence, when anexternal conductive object approaches but not contact the touch screen120, the touch sensitive processing apparatus 110 may detect aapproaching event but not a touching event. Since the deformation of theelastic dielectric layer 124 may be non-linear, the coordinates of theapproaching event is usually closer to a position that the user intendsto input comparing with the coordinates of the touching event. Thereforethe pressure calibration method 1100 is designed to calibrate themeasured pressure value corresponding to the coordinates of the touchingevent.

Step 1110: gathering an approaching event. Person having ordinary skillin the art can understand that the approaching event may be gatheredaccording to self-capacitance sensing or mutual-capacitance sensing.

Step 1120: gathering a touching event corresponding to the approachingevent by utilizing the mutual-capacitance sensing. As discussed above,there may not be a touching event corresponding to the approachingevent. Step 1120 is designed to find out whether the approaching eventwhich is corresponding to the touching event.

Step 1130: looking for the calibration area according to the coordinatesof the approaching event. A difference to step 1020 is that step 1130looks for the calibration area according to coordinates of theapproaching event, not according to coordinates of the touching event.In case that all areas around the corners and the edges of the touchscreen 120 have corresponding calibration areas, the flow may directlyproceed to step 1160. However, in case that the areas around the cornersand the edges of the touch screen 120 are not corresponding tocalibration areas, the flow may proceed to step 1140.

Step 1140: determining whether the approaching event is notcorresponding to any calibration area, i.e., in case the approachingevent is happened around the corners or the edges, the flow proceeds tostep 1150. Otherwise, the flow proceeds to step 1160.

Step 1150: looking for the closest calibration area according to thecoordinates of the approaching event. As discussed above, the closestfirst calibration area or the fourth calibration area may be designatedas the corresponding calibration area.

Step 1160: calculating a calibrated pressure value according to themeasured pressure value of the coordinates of the approaching event andthe pressure calibration function of the corresponding calibration area.

According to an embodiment of the present application, a pressurecalibration method is provided. The pressure calibration method isapplicable to a touch panel which sequentially comprises a layer offirst electrodes, an elastic dielectric layer, and a layer of secondelectrodes. The layer of first electrodes includes multiple firstelectrodes in parallel to a first axis. The layer of second electrodesincludes multiple second electrodes in parallel to a second axis. Thepressure calibration method comprising: gathering a touching event byutilizing mutual capacitance sensing between the first electrodes andthe second electrodes; looking for a corresponding calibration areaaccording to coordinates of the touching event; and calculating acalibrated pressure value according to a measured pressure valuecorresponding to the touching event and a pressure calibration functioncorresponding to the calibration area.

Preferably, in order to reduce memory space for storing calibrationareas and their corresponding pressure calibration functions, thepressure calibration method further comprises: when a calibration areawhere the touching event locates exists, taking the found calibrationarea as the corresponding calibration area; and when no calibration areawhere the touching event locates exists, taking a nearby calibrationarea which is closest to the touching event as the correspondingcalibration area.

Preferably, in order to reduce calculations of the pressure calibrationfunctions when the calibration points are designated to intersections ofthe first electrodes and the second electrodes, the calibration area isone of followings: a triangle, wherein two edges of the triangle are inparallel to two adjacent edges of the touch panel, respectively; and arectangle, wherein two adjacent edges of the rectangle are in parallelto two adjacent edges of the touch panel, respectively.

Preferably, in order to cope with variations of measured pressure valuescorresponding to the calibration area, the pressure calibration functionis based on coordinates of at least one vertex of the calibration area,at least one standard test pressure value and at least one measuredpressure value.

Preferably, in order to conveniently designate coordinates of thevertexes and to measure at an intersection where one of the firstelectrodes is closest to one of the second electrodes, the vertexes aredesignated to intersections of the first electrodes and the secondelectrodes.

According to an embodiment of the present application, a pressurecalibration method is provided. The pressure calibration method isapplicable to a touch panel which sequentially comprises a layer offirst electrodes, an elastic dielectric layer, a layer of secondelectrodes. The layer of first electrodes includes multiple firstelectrodes in parallel to a first axis. The layer of second electrodesincludes multiple second electrodes in parallel to a second axis. Thetouch panel further includes multiple third layers in parallel to thefirst axis. The pressure calibration method comprising: gathering anapproaching event by utilizing the second electrodes and the thirdelectrodes; gathering a touching event corresponding to the approachingevent by utilizing mutual capacitance sensing between the firstelectrodes and the second electrodes; looking for a calibration areaaccording to the approaching event; and calculating a calibratedpressure value according to a measured pressure value corresponding tothe approaching event and a pressure calibration function correspondingto the calibration area.

Preferably, in order to reduce memory space for storing calibrationareas and their corresponding pressure calibration functions, thepressure calibration method further comprises: when a calibration areawhere the approaching event locates exists, taking the found calibrationarea as the corresponding calibration area; and when no calibration areawhere the touching event locates exists, taking a nearby calibrationarea which is closest to the approaching event as the correspondingcalibration area.

Preferably, in order to reduce calculations of the pressure calibrationfunctions when the calibration points are designated to intersections ofthe first electrodes and the second electrodes, the calibration area isone of followings: a triangle, wherein two edges of the triangle are inparallel to two adjacent edges of the touch panel, respectively; and arectangle, wherein two adjacent edges of the rectangle are in parallelto two adjacent edges of the touch panel, respectively.

Preferably, in order to cope with variations of measured pressure valuescorresponding to the calibration area, the pressure calibration functionis based on coordinates of at least one vertex of the calibration area,at least one standard test pressure value and at least one measuredpressure value.

Preferably, in order to conveniently designate coordinates of thevertexes and to measure at an intersection where one of the firstelectrodes is closest to one of the second electrodes, the vertexes aredesignated to intersections of the first electrodes and the secondelectrodes.

According to an embodiment of the present application, a touch sensitiveprocessing apparatus for pressure calibration is provided. The touchsensitive processing apparatus is coupled to a touch panel whichsequentially comprises a layer of first electrodes, an elasticdielectric layer, and a layer of second electrodes. The layer of firstelectrodes includes multiple first electrodes in parallel to a firstaxis. The layer of second electrodes includes multiple second electrodesin parallel to a second axis. The touch sensitive processing apparatuscomprising: an interconnection network, configured to connect to one ormore the first electrodes and one or more the second electrodes,respectively; a driving circuit, configured to connect to theinterconnection network for transmitting driving signals; a sensingcircuit, configured to connect to the interconnection network forsensing induced driving signals; and a processor, coupled to theinterconnection network, the driving circuit and the sensing circuit,configured to execute instructions stored in a non-volatile memory torealize the following steps: gathering a touching event by utilizingmutual capacitance sensing between the first electrodes and the secondelectrodes; looking for a corresponding calibration area according tocoordinates of the touching event; and calculating a calibrated pressurevalue according to a measured pressure value corresponding to thetouching event and a pressure calibration function corresponding to thecalibration area.

Preferably, in order to reduce memory space for storing calibrationareas and their corresponding pressure calibration functions, theprocessor is further configured to realize the following steps: when acalibration area where the touching event locates exists, taking thefound calibration area as the corresponding calibration area; and whenno calibration area where the touching event locates exists, taking anearby calibration area which is closest to the touching event as thecorresponding calibration area.

Preferably, in order to reduce calculations of the pressure calibrationfunctions when the calibration points are designated to intersections ofthe first electrodes and the second electrodes, the calibration area isone of followings: a triangle, wherein two edges of the triangle are inparallel to two adjacent edges of the touch panel, respectively; and arectangle, wherein two adjacent edges of the rectangle are in parallelto two adjacent edges of the touch panel, respectively.

Preferably, in order to cope with variations of measured pressure valuescorresponding to the calibration area, the pressure calibration functionis based on coordinates of at least one vertex of the calibration area,at least one standard test pressure value and at least one measuredpressure value.

Preferably, in order to conveniently designate coordinates of thevertexes and to measure at an intersection where one of the firstelectrodes is closest to one of the second electrodes, the vertexes aredesignated to intersections of the first electrodes and the secondelectrodes.

According to an embodiment of the present application, a touch sensitiveprocessing apparatus for pressure calibration is provided. The touchsensitive processing apparatus is coupled to a touch panel whichsequentially comprises a layer of first electrodes, an elasticdielectric layer, and a layer of second electrodes. The layer of firstelectrodes includes multiple first electrodes in parallel to a firstaxis. The layer of second electrodes includes multiple second electrodesin parallel to a second axis. The touch panel further includes multiplethird layers in parallel to the first axis. The touch sensitiveprocessing apparatus comprising: an interconnection network, configuredto connect to one or more the first electrodes, one or more the secondelectrodes and one or more the third electrodes, respectively; a drivingcircuit, configured to connect to the interconnection network fortransmitting driving signals; a sensing circuit, configured to connectto the interconnection network for sensing induced driving signals; anda processor, coupled to the interconnection network, the driving circuitand the sensing circuit, configured to execute instructions stored in anon-volatile memory to realize the following steps: gathering anapproaching event by utilizing the second electrodes and the thirdelectrodes; gathering a touching event corresponding to the approachingevent by utilizing mutual capacitance sensing between the firstelectrodes and the second electrodes; looking for a calibration areaaccording to the approaching event; and calculating a calibratedpressure value according to a measured pressure value corresponding tothe approaching event and a pressure calibration function correspondingto the calibration area.

Preferably, in order to reduce memory space for storing calibrationareas and their corresponding pressure calibration functions, theprocessor is further configured to realize following steps: when acalibration area where the approaching event locates exists, taking thefound calibration area as the corresponding calibration area; and whenno calibration area where the touching event locates exists, taking anearby calibration area which is closest to the approaching event as thecorresponding calibration area.

Preferably, in order to reduce calculations of the pressure calibrationfunctions when the calibration points are designated to intersections ofthe first electrodes and the second electrodes, the calibration area isone of followings: a triangle, wherein two edges of the triangle are inparallel to two adjacent edges of the touch panel, respectively; and arectangle, wherein two adjacent edges of the rectangle are in parallelto two adjacent edges of the touch panel, respectively.

Preferably, in order to cope with variations of measured pressure valuescorresponding to the calibration area, the pressure calibration functionis based on coordinates of at least one vertex of the calibration area,at least one standard test pressure value and at least one measuredpressure value.

Preferably, in order to conveniently designate coordinates of thevertexes and to measure at an intersection where one of the firstelectrodes is closest to one of the second electrodes, the vertexes aredesignated to intersections of the first electrodes and the secondelectrodes.

According to an embodiment of the present application, a touch systemfor pressure calibration is provided. The touch system comprising theaforementioned touch sensitive processing apparatus; and the touch panelcoupled to the touch sensitive processing apparatus.

According to an embodiment of the present application, a pressurecalibration function calculation method is provided. The pressurecalibration function calculation method is applied to a touch panelwhich sequentially comprises a layer of first electrodes, an elasticdielectric layer, and a layer of second electrodes. The layer of firstelectrodes includes multiple first electrodes in parallel to a firstaxis. The layer of second electrodes includes multiple second electrodesin parallel to a second axis. The pressure calibration functioncalculation method comprising: by utilizing mutual capacitance sensingbetween the first electrodes and the second electrodes, measuringpressure values corresponding to calibration points when being pressedby a standard test pressure value, wherein the touch panel comprisesmultiple calibration areas and each calibration area corresponds to oneor more of the calibration points; and calculating a pressurecalibration function corresponding to each of the calibration areasaccording to coordinates of the calibration points, the standard testpressure value and the measured pressure values of the calibrationpoints.

Preferably, in order to further calibrate around the calibration pointcorresponding to abnormal measured pressure value, the pressurecalibration function calculation method further comprises: determiningwhether the measured pressure values corresponding to the calibrationpoints are out of a range; when one of the measured pressure values isdetermined out of the range, designating a special calibration area,wherein the special calibration area comprises multiple specialcalibration points and the calibration point corresponding to themeasured pressure value which is out of the range; by utilizing mutualcapacitance sensing between the first electrodes and the secondelectrodes, measuring pressure values corresponding to the specialcalibration points when being pressed by the standard test pressurevalue; and calculating a pressure calibration function corresponding tothe special calibration area according to coordinates of the specialcalibration points, the standard test pressure value and the measuredpressure values of the special calibration points.

Preferably, in order to reduce calculations of the pressure calibrationfunctions when the calibration points are designated to intersections ofthe first electrodes and the second electrodes, the calibration area isone of followings: a triangle, wherein two edges of the triangle are inparallel to two adjacent edges of the touch panel, respectively; and arectangle, wherein two adjacent edges of the rectangle are in parallelto two adjacent edges of the touch panel, respectively.

Preferably, in order to conveniently designate coordinates of thevertexes and to measure at an intersection where one of the firstelectrodes is closest to one of the second electrodes, the vertexes aredesignated to intersections of the first electrodes and the secondelectrodes.

Preferably, in order to provide the pressure calibration functioncorresponding to a triangular or a rectangular calibration area, thepressure calibration function is denoted as ƒ(P_(m))=P_(c)=r·P_(m)+e,where P_(m) is a measured pressure value, P_(c) is a calibrated pressurevalue, r is a coefficient of calibration, e is an error value, when therectangular calibration area is corresponding to four of the calibrationpoints at (x₀, y₀), (x₁, y₀), (x₁, y₁) and (x₀, y₁), respectively, andtheir coefficients are r_(0,0), r_(1,0), r_(1,1) and r_(0,1),respectively, the coefficient r of a point (x, y) in the calibrationarea is denoted as

${r = {r_{0,0} + {\frac{r_{0,1} - r_{0,0}}{y_{1} - y_{0}}( {y - y_{0}} )} + {\frac{r_{1,0} - r_{0,0}}{x_{1} - x_{0}}( {x - x_{0}} )} + {\frac{( {r_{1,1} + r_{0,0}} ) - ( {r_{1,0} + r_{0,1}} )}{( {y_{1} - y_{0}} )( {x_{1} - x_{0}} )}( {x - x_{0}} )( {y - y_{0}} )}}},$

when the rectangular calibration area is corresponding to two of thecalibration points at (x₀, y₀) and (x₁, y₀), respectively, and theircoefficients are r_(0,0) and r_(1,0), respectively, the coefficient r ofa point (x, y) in the calibration area is denoted as

${r = {r_{0,0} + {\frac{r_{1,0} - r_{0,0}}{x_{1} - x_{0}}( {x - x_{0}} )}}},$

when the rectangular calibration area is corresponding to two of thecalibration points at (x₀, y₀) and (x₀, y₁), respectively, and theircoefficients are r_(0,0) and r_(0,1), respectively, the coefficient r ofa point (x, y) in the calibration area is denoted as

${r = {r_{0,0} + {\frac{r_{0,1} - r_{0,0}}{y_{1} - y_{0}}( {y - y_{0}} )}}},$

when the triangular calibration area is corresponding to three of thecalibration points at (x₀, y₀), (x₁, y₀) and (x₁, y₁), respectively, andtheir coefficients are r_(0,0), r_(1,0) and r_(1,1), respectively, thecoefficient r of a point (x, y) in the calibration area is denoted as

${r = {r_{0,0} + {\frac{r_{1,0} - r_{0,0}}{x_{1} - x_{0}}( {x - x_{0}} )} + {\frac{r_{1,1} - r_{1,0}}{y_{1} - y_{0}}( {y - y_{0}} )}}},$

when the triangular calibration area is corresponding to three of thecalibration points at (x₀, y₀), (x₀, y₁) and (x₁, y₁), respectively, andtheir coefficients are r_(0,0), r_(0,1) and r_(1,1), respectively, thecoefficient r of a point (x, y) in the calibration area is denoted as

$r = {r_{0,0} + {\frac{r_{0,1} - r_{0,0}}{y_{1} - y_{0}}( {y - y_{0}} )} + {\frac{r_{1,1} - r_{0,1}}{x_{1} - x_{0}}{( {x - x_{0}} ).}}}$

According to an embodiment of the present application, a touch sensitiveprocessing apparatus for pressure calibration function calculation isprovided. The sensitive processing apparatus is coupled to a touch panelwhich sequentially comprises a layer of first electrodes, an elasticdielectric layer, and a layer of second electrodes. The layer of firstelectrodes includes multiple first electrodes in parallel to a firstaxis. The layer of second electrodes includes multiple second electrodesin parallel to a second axis. The touch sensitive processing apparatuscomprising: an interconnection network, configured to connect one ormore the first electrodes and one or more the second electrodes; adriving circuit, configured to transmit driving signals via theinterconnection network, a sensing circuit, configured to sense induceddriving signals via the interconnection network; and a processor,coupled to the interconnection network, the driving circuit and thesensing circuit, configured to execute instructions stored innon-volatile memory to realize the following steps: by utilizing mutualcapacitance sensing between the first electrodes and the secondelectrodes, measuring pressure values corresponding to calibrationpoints when being pressed by a standard test pressure value, wherein thetouch panel comprises multiple calibration areas and each calibrationarea corresponds to one or more of the calibration points; andcalculating a pressure calibration function corresponding to each of thecalibration areas according to coordinates of the calibration points,the standard test pressure value and the measured pressure values of thecalibration points.

Preferably, in order to further calibrate around the calibration pointcorresponding to abnormal measured pressure value, the processor isfurther configured to realize following steps: determining whether themeasured pressure values corresponding to the calibration points are outof a range; when one of the measured pressure values is determined outof the range, designating a special calibration area, wherein thespecial calibration area comprises multiple special calibration pointsand the calibration point corresponding to the measured pressure valuewhich is out of the range; by utilizing mutual capacitance sensingbetween the first electrodes and the second electrodes, measuringpressure values corresponding to the special calibration points whenbeing pressed by the standard test pressure value; and calculating apressure calibration function corresponding to the special calibrationarea according to coordinates of the special calibration points, thestandard test pressure value and the measured pressure values of thespecial calibration points.

Preferably, in order to reduce calculations of the pressure calibrationfunctions when the calibration points are designated to intersections ofthe first electrodes and the second electrodes, the calibration area isone of followings: a triangle, wherein two edges of the triangle are inparallel to two adjacent edges of the touch panel, respectively; and arectangle, wherein two adjacent edges of the rectangle are in parallelto two adjacent edges of the touch panel, respectively.

Preferably, in order to conveniently designate coordinates of thevertexes and to measure at an intersection where one of the firstelectrodes is closest to one of the second electrodes, the vertexes aredesignated to intersections of the first electrodes and the secondelectrodes.

Preferably, in order to provide the pressure calibration functioncorresponding to a triangular or a rectangular calibration area, thepressure calibration function is denoted as ƒ(P_(m))=P_(c)=r P_(m)+e,where P_(m) is a measured pressure value, P_(c) is a calibrated pressurevalue, r is a coefficient of calibration, e is an error value, when therectangular calibration area is corresponding to four of the calibrationpoints at (x₀, y₀), (x₁, y₀), (x₁, y₁) and (x₀, y₁), respectively, andtheir coefficients are r_(0,0), r_(1,0), r_(1,1) and r_(0,1),respectively, the coefficient r of a point (x, y) in the calibrationarea is denoted as

${r = {r_{0,0} + {\frac{r_{0,1} - r_{0,0}}{y_{1} - y_{0}}( {y - y_{0}} )} + {\frac{r_{1,0} - r_{0,0}}{x_{1} - x_{0}}( {x - x_{0}} )} + {\frac{( {r_{1,1} + r_{0,0}} ) - ( {r_{1,0} + r_{0,1}} )}{( {y_{1} - y_{0}} )( {x_{1} - x_{0}} )}( {x - x_{0}} )( {y - y_{0}} )}}},$

when the rectangular calibration area is corresponding to two of thecalibration points at (x₀, y₀) and (x₁, y₀), respectively, and theircoefficients are r_(0,0) and r_(1,0), respectively, the coefficient r ofa point (x, y) in the calibration area is denoted as

${r = {r_{0,0} + {\frac{r_{1,0} - r_{0,0}}{x_{1} - x_{0}}( {x - x_{0}} )}}},$

when the rectangular calibration area is corresponding to two of thecalibration points at (x₀, y₀) and (x₀, y₁), respectively, and theircoefficients are r_(0,0) and r_(0,1), respectively, the coefficient r ofa point (x, y) in the calibration area is denoted as

${r = {r_{0,0} + {\frac{r_{0,1} - r_{0,0}}{y_{1} - y_{0}}( {y - y_{0}} )}}},$

when the triangular calibration area is corresponding to three of thecalibration points at (x₀, y₀), (x₁, y₀) and (x₁, y₁), respectively, andtheir coefficients are r_(0,0), r_(1,0) and r_(1,1), respectively, thecoefficient r of a point (x, y) in the calibration area is denoted as

${r = {r_{0,0} + {\frac{r_{1,0} - r_{0,0}}{x_{1} - x_{0}}( {x - x_{0}} )} + {\frac{r_{1,1} - r_{1,0}}{y_{1} - y_{0}}( {y - y_{0}} )}}},$

when the triangular calibration area is corresponding to three of thecalibration points at (x₀, y₀), (x₀, y₁) and (x₁, y₁), respectively, andtheir coefficients are r_(0,0), r_(0,1) and r_(1,1), respectively, thecoefficient r of a point (x, y) in the calibration area is denoted as

$r = {r_{0,0} + {\frac{r_{0,1} - r_{0,0}}{y_{1} - y_{0}}( {y - y_{0}} )} + {\frac{r_{1,1} - r_{0,1}}{x_{1} - x_{0}}{( {x - x_{0}} ).}}}$

According to an embodiment of the present application, a touch systemfor pressure calibration function calculation is provided. The touchsystem comprising the aforementioned touch sensitive processingapparatus; and the touch panel coupled to the touch sensitive processingapparatus.

While the invention has been described in terms of what is presentlyconsidered to be the most practical and preferred embodiments, it is tobe understood that the invention needs not to be limited to the aboveembodiments. On the contrary, it is intended to cover variousmodifications and similar arrangements included within the spirit andscope of the appended claims which are to be accorded with the broadestinterpretation so as to encompass all such modifications and similarstructures.

What is claimed is:
 1. A pressure calibration method, applicable to atouch panel which sequentially comprises a layer of first electrodes, anelastic dielectric layer, and a layer of second electrodes, the layer offirst electrodes includes multiple first electrodes in parallel to afirst axis, the layer of second electrodes includes multiple secondelectrodes in parallel to a second axis, the pressure calibration methodcomprising: gathering a touching event by utilizing mutual capacitancesensing between the first electrodes and the second electrodes; lookingfor a corresponding calibration area according to coordinates of thetouching event; when a calibration area where the touching event locatesexists, taking the found calibration area as the correspondingcalibration area; when no calibration area where the touching eventlocates exists, taking a nearby calibration area which is closest to thetouching event as the corresponding calibration area; and calculating acalibrated pressure value according to a measured pressure valuecorresponding to the touching event and a pressure calibration functioncorresponding to the calibration area.
 2. The pressure calibrationmethod recited in claim 1, wherein the calibration area is one offollowing: a triangle, wherein two edges of the triangle are in parallelto two adjacent edges of the touch panel, respectively; and a rectangle,wherein two adjacent edges of the rectangle are in parallel to twoadjacent edges of the touch panel, respectively.
 3. A pressurecalibration method, applicable to a touch panel which sequentiallycomprises a layer of first electrodes, an elastic dielectric layer, alayer of second electrodes, the layer of first electrodes includesmultiple first electrodes in parallel to a first axis, the layer ofsecond electrodes includes multiple second electrodes in parallel to asecond axis, the touch panel further includes multiple third layers inparallel to the first axis, wherein the pressure calibration methodcomprising: gathering an approaching event by utilizing the secondelectrodes and the third electrodes; gathering a touching eventcorresponding to the approaching event by utilizing mutual capacitancesensing between the first electrodes and the second electrodes; lookingfor a calibration area according to the approaching event; when acalibration area where the approaching event locates exists, taking thefound calibration area as the corresponding calibration area; when nocalibration area where the touching event locates exists, taking anearby calibration area which is closest to the approaching event as thecorresponding calibration area; and calculating a calibrated pressurevalue according to a measured pressure value corresponding to theapproaching event and a pressure calibration function corresponding tothe calibration area.
 4. The pressure calibration method recited inclaim 3, wherein the calibration area is one of following: a triangle,wherein two edges of the triangle are in parallel to two adjacent edgesof the touch panel, respectively; and a rectangle, wherein two adjacentedges of the rectangle are in parallel to two adjacent edges of thetouch panel, respectively.
 5. A touch sensitive processing apparatus forpressure calibration, wherein the touch sensitive processing apparatusis coupled to a touch panel which sequentially comprises a layer offirst electrodes, an elastic dielectric layer, and a layer of secondelectrodes, the layer of first electrodes includes multiple firstelectrodes in parallel to a first axis, the layer of second electrodesincludes multiple second electrodes in parallel to a second axis,wherein the touch sensitive processing apparatus comprising: aninterconnection network, configured to connect to one or more the firstelectrodes and one or more the second electrodes, respectively; adriving circuit, configured to connect to the interconnection networkfor transmitting driving signals; a sensing circuit, configured toconnect to the interconnection network for sensing induced drivingsignals; and a processor, coupled to the interconnection network, thedriving circuit and the sensing circuit, configured to executeinstructions stored in a non-volatile memory to realize the followingsteps: gathering a touching event by utilizing mutual capacitancesensing between the first electrodes and the second electrodes; lookingfor a corresponding calibration area according to coordinates of thetouching event; when a calibration area where the touching event locatesexists, taking the found calibration area as the correspondingcalibration area; when no calibration area where the touching eventlocates exists, taking a nearby calibration area which is closest to thetouching event as the corresponding calibration area; and calculating acalibrated pressure value according to a measured pressure valuecorresponding to the touching event and a pressure calibration functioncorresponding to the calibration area.
 6. The touch sensitive processingapparatus recited in claim 5, wherein the calibration area is one offollowing: a triangle, wherein two edges of the triangle are in parallelto two adjacent edges of the touch panel, respectively; and a rectangle,wherein two adjacent edges of the rectangle are in parallel to twoadjacent edges of the touch panel, respectively.
 7. A touch sensitiveprocessing apparatus for pressure calibration, wherein the touchsensitive processing apparatus is coupled to a touch panel whichsequentially comprises a layer of first electrodes, an elasticdielectric layer, and a layer of second electrodes, the layer of firstelectrodes includes multiple first electrodes in parallel to a firstaxis, the layer of second electrodes includes multiple second electrodesin parallel to a second axis, the touch panel further includes multiplethird layers in parallel to the first axis, wherein the touch sensitiveprocessing apparatus comprising: an interconnection network, configuredto connect to one or more the first electrodes and one or more thesecond electrodes, respectively; a driving circuit, configured toconnect to the interconnection network for transmitting driving signals;a sensing circuit, configured to connect to the interconnection networkfor sensing induced driving signals; and a processor, coupled to theinterconnection network, the driving circuit and the sensing circuit,configured to execute instructions stored in a non-volatile memory torealize the following steps: gathering an approaching event by utilizingthe second electrodes and the third electrodes; gathering a touchingevent corresponding to the approaching event by utilizing mutualcapacitance sensing between the first electrodes and the secondelectrodes; looking for a calibration area according to the approachingevent; when a calibration area where the approaching event locatesexists, taking the found calibration area as the correspondingcalibration area; when no calibration area where the touching eventlocates exists, taking a nearby calibration area which is closest to theapproaching event as the corresponding calibration area; and calculatinga calibrated pressure value according to a measured pressure valuecorresponding to the approaching event and a pressure calibrationfunction corresponding to the calibration area.
 8. The touch sensitiveprocessing apparatus recited in claim 7, wherein the calibration area isone of following: a triangle, wherein two edges of the triangle are inparallel to two adjacent edges of the touch panel, respectively; and arectangle, wherein two adjacent edges of the rectangle are in parallelto two adjacent edges of the touch panel, respectively.
 9. A touchsystem for pressure calibration, comprising: the touch sensitiveprocessing apparatus recited in claim 5; and the touch panel coupled tothe touch sensitive processing apparatus.
 10. A touch system forpressure calibration, comprising: the touch sensitive processingapparatus recited in claim 6; and the touch panel coupled to the touchsensitive processing apparatus.
 11. A touch system for pressurecalibration, comprising: the touch sensitive processing apparatusrecited in claim 7; and the touch panel coupled to the touch sensitiveprocessing apparatus.
 12. A touch system for pressure calibration,comprising: the touch sensitive processing apparatus recited in claim 8;and the touch panel coupled to the touch sensitive processing apparatus.